The present invention relates to ablator compositions for protecting the underlying structure of a spacecraft or the like from the aerodynamic heating caused by travel at high speed during reentry through the atmosphere or caused by contact with gas and the like upon combustion of the propellant. An ablating material which is to be applied to the exterior of the underlying structure is prepared by curing the ablator composition.
British Patent Specification 1255132 discloses an ablative coating composition for protecting the surfaces of aerospace vehicles from the eroding effect of hot gases. This composition comprises: (A) 100 parts by weight of a silicone elastomer, (B) 1.0-100 parts by weight of silicon carbide, (C) 1.0-250 parts by weight of silica, and (D) 0.1-15 parts by weight of a high temperature decomposing fiber which melts at a temperature above 1650.degree. C.
Recently, there has been an increasing demand for ablating materials which are further improved in thermal protection and further lowered in ablation rate.